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Hornet down in Townsville............


Guest Maj Millard

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Guest Maj Millard

Brand new Hornet 19-7948 which arrived at Montpelier last weekend from taree, suffered an engine stoppage today and sits in a grassy field near the Ross River dam, not far from home base. Appears the pilot was switching fuel tanks enroute. From reports he turned the old tank off, and didn't select the new tank quick enough, resulting in fuel starvation to the engine. The correct proceedure by the way, is to turn the new tank on first, and then turn the old tank off !....Don't know what height he was when the stoppage occurred, or if an inflight restart was attempted.

 

From a flyover it appears the left undercarrage has collapsed, and there is also LH wing damage. The two occupants escaped unharmed.............................................................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

 

 

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Brand new Hornet 19-7948 which arrived at Montpelier last weekend from taree, suffered an engine stoppage today and sits in a grassy field near the Ross River dam, not far from home base................Maj...024_cool.gif.7a88a3168ebd868f5549631161e2b369.gif

That will hurt in so many ways. Maj. 036_faint.gif.544c913aae3989c0f13fd9d3b82e4e2c.gif

 

Hard to bend an aeroplane anytime, even harder if it's new and harder still if it's your own fault. Quite a lesson, I guess?

 

Still, the positives are that the occupants are ok and the aircraft can be rebuilt.

 

kaz

 

 

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Guest Maj Millard

No it was a side by side seat job with a 912uls up front. Yes it did look rebuildable from my fly-over, so the owner will have something to do with his time for a few months, yes she was brand new, and yes always good when nobody gets hurt. Nice looking machine..pity.....I have some photos of the aircraft pre, and post-crash, which I will post later this evening................Maj...

 

 

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Guest Maj Millard

Yes all aircraft should have those Savannah-style header tanks IMOP...........................................................Maj...012_thumb_up.gif.cb3bc51429685855e5e23c55d661406e.gif

 

 

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Guest Maj Millard

So not only have they selected an empty tank, but they have also ignored the bright red sump low-fuel level light, and not used the 'push to test' function of that warning light as part of their pre-take-off checks. Why are they in the aircraft in the first place !!!!???.............Maj...033_scratching_head.gif.b541836ec2811b6655a8e435f4c1b53a.gif

 

 

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Accidents happen, you would think looking at the panel and seeing 2 offs on the fuel system would ring a bell or two, probably not if you have a lot of hours in a savannah. I wonder if idiot proofing planes sort of encourages sloppy airmanship?

 

 

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Guest Maj Millard

'sloppy airmanship" is an oxymoran, there can be no such thing. To practise 'airmanship' is to be organized and orderly, not sloppy............................................................Maj...

 

 

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Idiots prove you can't idiot-proof a plane, but neither can anyone justify fuel systems that can introduce air easily or be a trap to operate by their very design.

 

The pilot MUST fully understand his/her fuel system.

 

We are all used to getting into our car, Glancing at the fuel gauge at some stage and then adding fuel. At worst you have to thumb a lift and come back with a tin of fuel and add it..

 

This approach is not suitable for a flying situation. I trust I don't really have to spell out why..

 

The set-up that Maj is describing is an excellent one. Most engine failures at 50" are with the fuel selector "OFF".

 

I've known of people who have runout of fuel doing circuits. I don't know how to help them except to advise another hobby. Nev

 

 

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Why have a tank isolated anyway ? My J160 has isolating valves on each tank but they are let 'ON' at all times , and the tanks empty together (in theory anyway ) The factory a/c do not have isolating valves to prevent this very occurence from happening . Or am I missing something ?

 

Bob

 

 

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I'm sure you would be required to be able to turn the fuel off in any design, or isolate a tank, as well. Some installations have a fuel return which returns surplus fuel to one of the tanks, in flight. Many situations where the fuel tanks should empty together, don't empty together. There are always reasons for that. The more complex the system the more you must manage it. Some systems will not exhaust all the fuel in a tank in some situations. Can depend on aircraft attitude..You must really know your fuel system, especially how to operate it when near empty, though you should plan never to have that happen. An off field landing is always better to manage if it is done before the fuel is exhausted.. Nev

 

 

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Well I am no expert by any means but common sense is just that. The savannah system is common sense with some idiot proofing as well. I replaced my "bulb" indicator for the sump tank when the fuel starts to drain out with a 10mm flashing LEDand its placed right in front of my face not off to the side. I have all 4 tanks switchable and the switches in a easy position to see at a glance what tanks are on or off. Obviously fuel management while flying is a given but as we have seen it can be forgotten or mis calculated even by experienced pilots. The sump indicator is a fallback just in case. I dont think it is idiot proofing but more like another layer of protection for human factors and a very valuable asset in any aircraft

 

Mark

 

 

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Guest Maj Millard

I'm happy that my original post has spurred a good discussion of fuel systems, which is always good.

 

Let me say at this point that I don't think the design of the Hornet fuel system had anything to do with this incident. I know Olies' workmanship, and he designs and builds a fine, and capable aircraft.

 

In answer to biggles question...I suppose there is no drama in having both tanks always on. There should however be a way to turn off fuel to the engine, for various reasons.

 

Most aircraft give the pilot the choice to draw fuel from a selected tank, and to alternate between tanks. For instance the Lightwing has, like many other aircraft, a tank in each wing plus an auxilary long-range tank (20 lts)below the fuselage. This aux tank pumps up into the RH tank only, when required.

 

So after take-off with both tanks selected (as with landing), I'll draw initally from the RH tank, then alternate every 30 mns between L and R. When 20 lts has been used from the RH, I can then pump the fuel up from the Aux. Often one wing tank will draw quicker than the other, so alternating tanks allows the pilot the option of keep similiar quanties in each tank, or to drain one more than the other, for lateral balance. This is especially handy if your flying solo in a side by side aircraft. I rarely drain a tank dry, and always attempt to land with similiar amounts in each side.................................................................Maj...012_thumb_up.gif.cb3bc51429685855e5e23c55d661406e.gif

 

 

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I think the design would be alright also. Perhaps one tank was exhausted and the other was not available quick enough.

 

If both tanks are equally able to supply fuel then making then common is ok, but at the back of my mind when I see one tank much lower that the other , I worry about air getting into the system even though there is fuel in abundance in the other tank.

 

The only assured way of getting all of the available fuel out of two tamks is to have two fuel pumps ,( One in eack tank), and a non return valve at the outlet of each tank. With both pumps on, ( as for T/O and landing), when a tank is exhausted , the pump will cavitate and won't pump air and the other pump which is not cavitating, because there is still fuel in the tank, will keep the system pressured so air will not enter till both tanks are completely empty. Nev

 

 

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Yes all aircraft should have those Savannah-style header tanks IMOP...........................................................Maj...012_thumb_up.gif.cb3bc51429685855e5e23c55d661406e.gif

It is interesting that the editor of this month's Zenair News from the USA are suggesting that Zenith builders should consider a Savannah-style header tank (without mentioning the Savannah, of course!) for fuel safety and weight reduction (the latter because running around with 'reserves' in normal fuel tanks means that the average pilot carries at least 30 lb too much fuel).

 

 

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Somebody mentioned airmanship earlier. Basic rule "don't turn fuel tanks off unless you have a leak or are working on the system" and if you do have a leak you should be looking for a place to land very quickly.

 

RickH

 

 

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There are a number of valid reasons why you should be able to switch tanks off and be able to specifically select fuel from a nominated tank in any aircraft that has the capacity to travel long distances. One obvious one is that by progressively selecting tanks you can be guaranteed of precise fuel available quantities at each tank switch.

 

May I suggest that the reason this mistake was made may have been a lack of knowledge of the Hornet systems. How much time did this pilot spend with the manufacturer flying the aircraft before taking delivery and departing for Nth Qld? Ollie is a very thorough gentleman and he would normally insist on a thorough familiarization before taking delivery of one of his aircraft.

 

 

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Guest davidh10

I wouldn't have thought that it would take much familiarity with a fuel system to understand that if you turn ALL tanks OFF, then the engine is going to stop.

 

Sounds like a HF error. Most likely, didn't check that one tank was turned on before turning the other off.

 

 

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